1. Field of the Invention
The present invention relates to a waterproof switch, and particularly to a waterproof switch suitable for enhancing its waterproof functions and for improving workability with which to attach a sealing member for waterproofness to the waterproof switch.
2. Description of the Related Art
A rear stop switch has been known as a switch which detects brake operations in response to a movement of a foot brake of a motorcycle or the like, and which thus lights a stop lamp. In a case of a rear stop switch of a conventional type, for example, a plunger is accommodated in a cylindrical case in a state where an end of the plunger penetrates through a sealing member and juts out of the case, and a spring member applies a force to the plunger toward the interior of the case. Lead contact points are configured to be capable of engaging with a contact point provided to the other end of the plunger, that is, a contact point provided to a portion in the interior of the case. This configuration makes the lead contact points engage (come into contact) with the contact point, and thus causes a detection signal indicating a stop operation to be outputted, if the stop operation draws the plunger out of the case against the spring. A switch of this type is disclosed, for example, in the specification of Utility Model Application Sho. 57-166347 (Unexamined Utility Model Application Publication Sho. 59-70884).
In a case of a rear stop switch of a conventional type described in Patent Document 1, when assembling the rear stop switch, first of all, a seal and a spring member (a coil spring) are attached to the bottom portion of a cylindrical case. Subsequently, a plunger is caused to penetrate through the coil spring and the seal. During this work, it is likely that the seal may be out of place because the plunger and the coil spring interferes with the seal. For this reason, in the conventional practice, it takes a long time to carry out the assembling work.
In addition, it is difficult to visibly check on the bottom portion of the cylindrical case. For this reason, as well, it takes much labor to make the visible check in some cases. With this taken in consideration, there has been a demand that the seal be attached to the rear stop switch efficiently by improving the time- and labor-consuming work.
On the other hand, the seal is used for making the rear stop switch not only waterproof but also dust-resistant. For this reason, that has been a demand that latitude of design be enlarged by using a larger seal for the purpose of enhancing the waterproofness and dust-resistance of the rear stop switch. If, however, the outer diameter of the seal is made larger than the outer diameter of the coil in the coil spring, this enlargement affects the expansion and contraction of the coil spring. This makes it impossible to enlarge the size of the seal.